Sound problems during calls

I am having a problem when talking to friends over Skype using a headset, and I am not sure why. Over the duration of the call, the other people in the call hear a static that progressively gets worse, and disappears once I mute my microphone. They can also hear my sounds from games and music, even when my mic is muted. I've tried adjusting some settings but nothing seems to work, could it be a loose connection inside of my PC?